I used to use Gargoyle shooting glasses, which had good peripheral vision, and were very resistant to scratches. I then switched to various Oakley glasses, until settling on Oakley Juliets. These have titanium frames, and the first pair I about back in 1998 are still in good shape, I send them to Oakley every couple of years to get refurbished.

So long as the glasses can keep out the UV, spray, dust, gravel, and insects, they are fine with me. I rely as much on my hearing as my eyes when I am riding, and I can usually hear things coming up which I cannot see.